I need to remove a sheet of metal attached with Bulbtite shavehead rivets. Any ideas on how to easily remove these without a rivet shaver? My friend is planning right now to use a air hammer as we don't care about the metal sheet.
Any ideas to be able to reuse the holes after the old rivets are out? The rivet spacing matches that on the rest of the bus and I went to maintain that if possible. Normally I just center punch the metal and drill all the way through. This doesn't work as well with existing holes. I am afraid the bit will catch the old holes and tear up my sheet of metal.
The bulbtite rivets that I used drill out very easily. I just take a 3/16 bit and drill the center out, or a bit bigger bit, then smack the bad-boy with a drift punch. That way I don't ream the existing hole too much.
I'm told that cherry rivets are a better critter for strength than the bulbtite I used. =)
What MattC said. Drill them out. If you use a chisel or air hammer, you run the risk of elongating the underlying holes.
If you are trying to match the holes in the frame with the new sheet, you can buy hole finders from the Yard Store that will locate the holes for you.
You can get either a center punch type, or a drill bit bushing type. Both work well.
What is the best way to get a starting spot for drilling out the rivet? I have not cut off the excess mandrel or shaved the head.
I am thinking I should take my grinder or dremel tool and cut a X in the top of each rivet so I have a way to center the drill bit.
A punch might work....
God bless,
John
Since you aren't worried about the finish, I'd just touch the little critters with a cut-off wheel in a grinder. I use a little Milwaukee that I can hold with one hand, and zip-zop the stubs gone and I have a flat starting surface.
For the keeper rivets, I use a dremel with an itty-bitty quick-change cutoff wheel to remove the mandrel and leave a pretty smooth surface. YMMV
As has been said, just drill them out...you don't need to find the exact center, as with a punch...just use a 3/16" drill and go to it, centering as you get started on each rivet.
If you are replacing these rivets with shaveheads, the exact roundness of the hole is not that critical as they 'clamp up' from the backside. If you were bucking solid rivets, then the roundness of the hole would be more of an issue.
For what it is worth, in our trailer/body industry the only thing we use a shaver for is to dress the head, not removing the entire rivet.
You could air hammer them off, but I think it would depend on how the metal sheets (etc) hold up to the impact hammer...if in doubt, drill them out.
I like the grinding/cutting them off idea as that would be faster than drilling out 75 rivets. Any reason this wouldn't work, or will I have troubles getting the old rivet clear of the hole?
There are two different types of rivet shavers and I think they are getting confused. A traditional rivet shaver is usually air powered and has a flat bit to cut a rivet head off so the metal can be removed with little or no damage. The rivet shaver for Bulbtite rivets is drill powered and has a curved bit to shape a shavehead rivet nicely. For this job I would uses a traditional rivet shaver if I had one.
I am going to have a heck of a time getting the metal off as I used poly caulk to seal the edges. It was intended to never come off.
I wonder if you could use a drywall screwdriver bit to center a mark on the rivet?
they make self centering punches in different sizes for those to mark and drill out the rivets fwiw good luck
I ended up cutting the heads off with a cutting wheel in my grinder. I didn't remove the sheet yet as I want to wait until I get the new sheet.
I'm not exactly sure how I will get the remaining part of the rivet removed right now.
Quote from: belfert on August 03, 2009, 07:30:23 PM
I ended up cutting the heads off with a cutting wheel in my grinder. I didn't remove the sheet yet as I want to wait until I get the new sheet.
I'm not exactly sure how I will get the remaining part of the rivet removed right now.
Ok, you're overthinking this simple task. With shaveheads, the mandrel is soft. To remove, just nip off with cutters near the head. Tap lightly with a small hammer to drive it flush with the head, and then use a center punch to drive it deeper into the head. Now you have a small hole in which to center you drill bit. Drill until the head comes off on the bit. Use the center punch to punch the remainder of the rivet into the framework. Don't punch too hard as the punch could expand the hole in the frame.
Done!
Atta boy Craig, that is just the way to do it, well said.
Sometimes folks seem to over-think things...maybe they just lots of time on their hands, what being retired and all with nothing to do all day but think about their bus!!!!!!!!!!!!!
I already have all of the rivet heads removed. After I remove the metal sheet I will then need to punch the remaining part of the rivet into the metal. I'll have to see if I need to cut off the rivets further or not.
I'm not retired and I don't have all day to think about this. I am just trying to make sure it doesn't get totally screwed up. I would rather not have to replace this panel, but my friend went ahead and started cutting the window hole and made it too big. Now I have to replace the panel and I would like the rivets to line up with the rest like they did on the original panel.
Then use a small center or flat pin punch to push the remainder of the rivets into the frame. Don't wedge the punch in the hole or you'll have to go up a size in rivets.
Get yourself a set of hole finders from The Yard Store (yardstore.com ??). They're not expensive.
I have a set you could borrow, but I'm leaving tomorrow for 3 weeks.
Quote from: gumpy on August 04, 2009, 03:49:57 PM
Get yourself a set of hole finders from The Yard Store (yardstore.com ??). They're not expensive.
I ordered some things called Tracermarkers. They basically stick in the hole and stick to back of the metal sheet when the sheet is held in place. Not cheap by any means, but I want the end result to ook good.
A regular hole finder would not fit on the two sides as the sheet is butted up against stuff on the two sides.
Update: Last night my friend and I got the new sheet of metal installed. We didn't use the Tracermarkers as they seemed to be one size too small and you only have one chance to get the metal into posiition.
We just laid the old sheet of metal on top of the new piece and used the old metal as a template. It worked pretty well although every hole along the bottom had to be redrilled once on the bus. None of the holes got big enough for the rivet to not cover the hole.
This was originally about removing the original rivets. We were able to punch in all but the four of the original 70+ rivets. Those four had to be drilled out.
I used 3/4" long rivets this time, but I still had one mandrel snap off prematurely. I'll be upset if I have to order some 1" loing rivets.
What rivets are you using?
I am using Bulbtite shavehead rivets.
Thanks.